Finally * * * conquered the lead in my SKS

[mpkunz]

Finally got the lead issue in my SKS worked out. Well, let's say I have a workable solution to my particular problem at this point.

After on going problems with lead fouling the gas piston I slugged the bore with a buckshot ball and found it to be an astonishing 0.314". I thought it was wear, but the lands were 0.300" on the money. Then I thought I musta made a mistake so I made a brass bullet on the lathe measuring 0.300" to just ride the lands and 0.314" to just fit into the grooves. The brass bullet weighed 148 grains and I fired it with 5.0 grains of Trail Mix into two 2x4's. Got stuck midway between them and held them together like a nail. I removed it and measured them. It was caked with lead, and sure enough, bore the marks that it was correctly sized the first time. It just barely touched land and grooves, only showing very light marks, and measured 0.300" and 0.314".

So I had some unsized lead 170 grainers from an 8mm LEE mould. I sized them to 0.315" and shot them. Shazzam. Finally, no lead on the gas piston. Only one problem. They now are just at the point that they sometimes jam upon feeding as they reach the throat.

So, I had enough today. Tomorrow I am building a reamer for the case mouths. That's been my solution to whomever might be interested, FWIW.

Mike

[Doc Highwall]

Now you have learned the importance of slugging and bullet fit.
It is so much easier when you do the right things instead of assuming and just go ahead and load ammo.

[mpkunz]

Now you have learned the importance of slugging and bullet fit.
It is so much easier when you do the right things instead of assuming and just go ahead and load ammo.

That was a tad condescending, Doc. And its not the case at all.

[Doc Highwall]

I did not mean it to be condescending. I and others here have done the same thing. I don't know if it was because we did not know, were lazy, or assumed our gun was perfect.
That is what I meant by when I said.
It is so much easier when you do the right things instead of assuming and just go ahead and load ammo.
In other words short cuts are just that, short on results. Ask me how I know.

[turbo1889]

I'm using 0.315" diameter in my SKS so you aren’t the only one that has one with a bore that is a little on the fat side to say the least. Is yours a Yugo as well (made in Russia specifically for Yugoslavia with shorter barrel then normal and a long flash hider that serves as a sleeve to fit inside a socket in Yugoslavian grenades and rockets designed to be launched from the muzzle with a bullet trap in the base of said grenade/rocket to catch the boolit and the flip up ladder sight for launching said munitions)?

I chose to open up the end of the neck area on the chamber by about 0.002” with a machinist’s straight reamer to match the bottom of the neck section of the chamber which was already oversize by that amount or slightly more. Now the shells with the oversize boolits chamber no problems. Left the throat alone since my boolits already fit in the guns throat no problem.

An alternative to thinning the necks of the brass, a lot more permanent, but an alternative you might consider.

[HARRYMPOPE]

if you shoot the biggest dia. bullet that will chamber easily its also a fairly good method.

HMP

[mpkunz]

Doc, my apologies for the response. Not my first encounter with the demons at the bore size rodeo.

This is a Yugo 59/66(?) with the fold under bayo and GL on the muzzle. Arrived via BBT about a month ago from JG Sales when they had a sale on them. After inspecting it I realized it was essentially a new rifle. Not even the usual wear in places where steel runs over steel, like the gas tube removing lever. I cleaned the bore with copper cleaner. I always like to do that when getting a milsurp arm ready to fire, but it didn't even have copper in the bore. Bore was shiny and bright, and the edges of the rifling were square and new, not rounded off. For my first shots I used Tiger and Wolf and they performed nicely. I was able to consistently tag a 10" armor gong I have set up at 185 yards. Cleaned it all up and put it away. At that point I was thinking I had gotten a really nice new rifle. Just didn't think that the barrel was going to be an issue after the way it performed.

Actually, it occurred to me that this might be a real life example of the ComBloc arms philosophy of "good enough is good enough". By US standards, the bore was out of spec. But by their standards, that really deep rifling (0.300 lands and 0.314" grooves) its holding onto production bullets tight enough to spin them and get good combat situation accuracy, nobody would notice any blowby, so for them it was "good enough".

Problem with shooting the biggest diameter boolit is as follows. 0.314" boolits are the top end that work without other issues. The 314's all chamber perfectly, but they still lead things up. 0.315" boolits don't lead things up, but about 1 in 4 get stuck when chambering, and I cannot get the bolt to close on them.

I'm glad you made mention of the idea of enlarging the neck in the chamber and leaving the throat alone. I really didn't want to go with modification of the gun in any way, but to deal with this I need to make a reamer anyhow, so I might as well make one that rides the bore and stays concentric with the bore. That in itself might just improve the accuracy a bit. But I really like the fact that once its fixed that's the end of the problem.

Thanks.

Mike

[Rico1950]

Yugoslavian grenades and rockets designed to be launched from the muzzle with a bullet trap in the base of said grenade/rocket to catch the boolit and the flip up ladder sight for launching said munitions)?

Blanks were used to fire the grenades and rockets. One country was blowing up their Yugos doing exactly that until they were told you had to use blanks!

[madsenshooter]

When it comes to jacketed, fit of the bullet to the bore isn't nearly as important. I used to think it was, then shot some Nosler 168s out of my .310 groove diameter Krag. Less than an inch at 100yds! Pressure has a tendency to escape around the bullet equally, which helps to keep the bullet centered as it rides down the rails of the rifling. I was expecting a 3 or 4 inch group, no where near what I got. Even Boots Obermeyer has been quoted as saying that in some cases, oversized barrels are surprisingly accurate. That's a pretty good lead removal system you came up with. If all else fails, blow it out!

[goofyoldfart]

MPKUNZ: Sounds like you have been listening to 303 guy in OZ on those brass bullets. :)) Still and all , that is one heck of a good way to clean, lap and de-lead the bore. Good going. God Bless to all.

Goofyoldfart <aka GOF<

[mpkunz]

MPKUNZ: Sounds like you have been listening to 303 guy in OZ on those brass bullets. :)) Still and all , that is one heck of a good way to clean, lap and de-lead the bore. Good going. God Bless to all.

Goofyoldfart <aka GOF<

I forgot to mention that I put several deep grooves, sharpened edge facing forward, so they could scrape and accumulate the lead that was fouling the rifling. Very effective. The first one was loaded with lead, the second one had almost nothing.

I'm need to get a replacement rubber stopper as I misplaced the original, but the final step in restoring it to original condition is the eletrolytic lead remover treatment with the Outers Foul Out gizmo. I've have amazing results with mine.